Low-dose oral methotrexate treatment in chronic progressive multiple sclerosis

Immunopathogenesis of multiple sclerosis: molecular and cellular mechanisms and new immunotherapeutic approaches

BACKGROUND

Multiple sclerosis (MS) is a central nervous system (CNS) demyelinating autoimmune disease with increasing global prevalence. It predominantly affects females, especially those of European descent. The interplay between environmental factors and genetic predisposition plays a crucial role in MS etiopathogenesis.

METHODS

We searched recent relevant literature on reputable databases, which include, PubMed, Embase, Web of Science, Scopus, and ScienceDirect using the following keywords: multiple sclerosis, pathogenesis, autoimmunity, demyelination, therapy, and immunotherapy.

RESULTS

Various animal models have been employed to investigate the MS etiopathogenesis and therapeutics. Autoreactive T cells within the CNS recruit myeloid cells through chemokine expression, leading to the secretion of inflammatory cytokines driving the MS pathogenesis, resulting in demyelination, gliosis, and axonal loss. Key players include T cell lymphocytes (CD4+ and CD8+), B cells, and neutrophils. Signaling dysregulation in inflammatory pathways and the immunogenetic basis of MS are essential considerations for any successful therapy to MS. Data indicates that B cells and neutrophils also have significant roles in MS, despite the common belief that T cells are essential. High neutrophil-to-lymphocyte ratios correlate with MS severity, indicating their contribution to disease progression. Dysregulated signaling pathways further exacerbate MS progression.

CONCLUSION

MS remains incurable, but disease-modifying therapies, monoclonal antibodies, and immunomodulatory drugs offer hope for patients. Research on the immunogenetics and immunoregulatory functions of gut microbiota is continuing to provide light on possible treatment avenues. Understanding the complex interplay between genetic predisposition, environmental factors, and immune dysregulation is critical for developing effective treatments for MS.

Safety of long-term intrathecal methotrexate in progressive forms of MS

Background

There are few treatment options for multiple sclerosis (MS) patients with advanced disability [expanded disability status scale (EDSS) ⩾ 6.0]. In 2010, we reported initial results of using intrathecal methotrexate (ITMTX) in patients with progressive MS. We now report on long-term use of ITMTX. We performed a retrospective chart analysis of patients who have had 18 or more treatments to establish the ongoing safety and tolerability of ITMTX. Thus, the objective of this study was to establish the safety and tolerability of long-term therapy with (ITMTX) in patients with treatment-resistant, progressive forms of MS.

Methods

We studied 83 patients (67 secondary and 16 primary progressive) who received ITMTX 12.5 mg every 8-11 weeks for 3-10 years (range: 18-57 treatments). All patients were evaluated neurologically, and their EDSS was assessed at every treatment. In addition, all adverse events, frequency of infections, and any hospitalizations, were noted.

Results

There were no deaths, hospitalizations, or other serious adverse effects related to ITMTX. Headaches occurred at least once in 12% of patients, and transient fatigue occurred in 53% of patients. As determined by EDSS, there was no significant change from baseline status to post-treatment scores in both primary progressive MS (PPMS) and secondary progressive (SPMS) patients.

Conclusions

Pulsed ITMTX was well tolerated for up to 10 years in PPMS patients with no serious adverse effects. Although this was an open-label, retrospective analysis, and efficacy could not be studied, there was evidence of disease stabilization in many patients receiving ITMTX. It appears that long-term ITMTX is a safe therapeutic option in advanced progressive MS.

Diagnosis and Management of Progressive Multiple Sclerosis

Multiple sclerosis is a chronic autoimmune disease of the central nervous system that results in varying degrees of disability. Progressive multiple sclerosis, characterized by a steady increase in neurological disability independently of relapses, can occur from onset (primary progressive) or after a relapsing-remitting course (secondary progressive). As opposed to active inflammation seen in the relapsing-remitting phases of the disease, the gradual worsening of disability in progressive multiple sclerosis results from complex immune mechanisms and neurodegeneration. A few anti-inflammatory disease-modifying therapies with a modest but significant effect on measures of disease progression have been approved for the treatment of progressive multiple sclerosis. The treatment effect of anti-inflammatory agents is particularly observed in the subgroup of patients with younger age and evidence of disease activity. For this reason, a significant effort is underway to develop molecules with the potential to induce myelin repair or halt the degenerative process. Appropriate trial methodology and the development of clinically meaningful disability outcome measures along with imaging and biological biomarkers of progression have a significant impact on the ability to measure the efficacy of potential medications that may reverse disease progression. In this issue, we will review current evidence on the physiopathology, diagnosis, measurement of disability, and treatment of progressive multiple sclerosis.

The role of oligodendrocytes and their progenitors on neural interface technology: A novel perspective on tissue regeneration and repair

Oligodendrocytes and their precursors are critical glial facilitators of neurophysiology, which is responsible for cognition and behavior. Devices that are used to interface with the brain allow for a more in-depth analysis of how neurons and these glia synergistically modulate brain activity. As projected by the BRAIN Initiative, technologies that acquire a high resolution and robust sampling of neural signals can provide a greater insight in both the healthy and diseased brain and support novel discoveries previously unobtainable with the current state of the art. However, a complex series of inflammatory events triggered during device insertion impede the potential applications of implanted biosensors. Characterizing the biological mechanisms responsible for the degradation of intracortical device performance will guide novel biomaterial and tissue regenerative approaches to rehabilitate the brain following injury. Glial subtypes which assist with neuronal survival and exchange of electrical signals, mainly oligodendrocytes, their precursors, and the insulating myelin membranes they produce, are sensitive to inflammation commonly induced from insults to the brain. This review explores essential physiological roles facilitated by oligodendroglia and their precursors and provides insight into their pathology following neurodegenerative injury and disease. From this knowledge, inferences can be made about the impact of device implantation on these supportive glia in order to engineer effective strategies that can attenuate their responses, enhance the efficacy of neural interfacing technology, and provide a greater understanding of the challenges that impede wound healing and tissue regeneration during pathology.

Progressive multiple sclerosis: from pathogenic mechanisms to treatment

During the past decades, better understanding of relapsing-remitting multiple sclerosis disease mechanisms have led to the development of several disease-modifying therapies, reducing relapse rates and severity, through immune system modulation or suppression. In contrast, current therapeutic options for progressive multiple sclerosis remain comparatively disappointing and challenging. One possible explanation is a lack of understanding of pathogenic mechanisms driving progressive multiple sclerosis. Furthermore, diagnosis is usually retrospective, based on history of gradual neurological worsening with or without occasional relapses, minor remissions or plateaus. In addition, imaging methods as well as biomarkers are not well established. Magnetic resonance imaging studies in progressive multiple sclerosis show decreased blood-brain barrier permeability, probably reflecting compartmentalization of inflammation behind a relatively intact blood-brain barrier. Interestingly, a spectrum of inflammatory cell types infiltrates the leptomeninges during subpial cortical demyelination. Indeed, recent magnetic resonance imaging studies show leptomeningeal contrast enhancement in subjects with progressive multiple sclerosis, possibly representing an in vivo marker of inflammation associated to subpial demyelination. Treatments for progressive disease depend on underlying mechanisms causing central nervous system damage. Immunity sheltered behind an intact blood-brain barrier, energy failure, and membrane channel dysfunction may be key processes in progressive disease. Interfering with these mechanisms may provide neuroprotection and prevent disability progression, while potentially restoring activity and conduction along damaged axons by repairing myelin. Although most previous clinical trials in progressive multiple sclerosis have yielded disappointing results, important lessons have been learnt, improving the design of novel ones. This review discusses mechanisms involved in progressive multiple sclerosis, correlations between histopathology and magnetic resonance imaging studies, along with possible new therapeutic approaches.

Evaluation of Study and Patient Characteristics of Clinical Studies in Primary Progressive Multiple Sclerosis: A Systematic Review

Background

So far, clinical studies in primary progressive MS (PPMS) have failed to meet their primary efficacy endpoints. To some extent this might be attributable to the choice of assessments or to the selection of the study population.

Objective

The aim of this study was to identify outcome influencing factors by analyzing the design and methods of previous randomized studies in PPMS patients without restriction to intervention or comparator.

Methods

A systematic literature search was conducted in MEDLINE, EMBASE, BIOSIS and the COCHRANE Central Register of Controlled Trials (inception to February 2015). Keywords included PPMS, primary progressive multiple sclerosis and chronic progressive multiple sclerosis. Randomized, controlled trials of at least one year’s duration were selected if they included only patients with PPMS or if they reported sufficient PPMS subgroup data. No restrictions with respect to intervention or comparator were applied. Study quality was assessed by a biometrics expert. Relevant baseline characteristics and outcomes were extracted and compared.

Results

Of 52 PPMS studies identified, four were selected. Inclusion criteria were notably different among studies with respect to both the definition of PPMS and the requirements for the presence of disability progression at enrolment. Differences between the study populations included the baseline lesion load, pretreatment status and disease duration. The rate of disease progression may also be an important factor, as all but one of the studies included a large proportion of patients with a low progression rate. In addition, the endpoints specified could not detect progression adequately.

Conclusion

Optimal PPMS study methods involve appropriate patient selection, especially regarding the PPMS phenotype and progression rate. Functional composite endpoints might be more sensitive than single endpoints in capturing progression.

Glatiramer acetate in treatment of multiple sclerosis: a toolbox of random co-polymers for targeting inflammatory mechanisms of both the innate and adaptive immune system?

Multiple sclerosis is a disease of the central nervous system, resulting in the demyelination of neurons, causing mild to severe symptoms. Several anti-inflammatory treatments now play a significant role in ameliorating the disease. Glatiramer acetate (GA) is a formulation of random polypeptide copolymers for the treatment of relapsing-remitting MS by limiting the frequency of attacks. While evidence suggests the influence of GA on inflammatory responses, the targeted molecular mechanisms remain poorly understood. Here, we review the multiple pharmacological modes-of-actions of glatiramer acetate in treatment of multiple sclerosis. We discuss in particular a newly discovered interaction between the leukocyte-expressed integrin α(M)β(2) (also called Mac-1, complement receptor 3, or CD11b/CD18) and perspectives on the GA co-polymers as an influence on the function of the innate immune system.

Methothrexate attenuates early neutrophil infiltration and the associated lipid peroxidation in the injured spinal cord but does not induce neurotoxicity in the uninjured spinal cord in rats

BACKGROUND

The goal of most acute therapies for spinal cord injury (SCI) in humans include attenuation of the early inflammatory response and may limit the extent of tissue injury and the consequent disability.

OBJECTIVE

The purpose of this study was to investigate the early effects of methothrexate (MTX) treatment on myeloperoxidase (MPO) activity, malondialdehyde (MDA) level, and ultrastructural findings in the injured and uninjured spinal cords of rats. The effects of MTX treatment were also compared with methylprednisolone sodium succinate (MPSS) treatment.

METHODS

Wistar rats were divided into seven groups: control; trauma alone (50 g/cm weight drop trauma); SCI + MPSS (30 mg/kg); SCI + low-dose (0.5 mg/kg) MTX (LDMTX); SCI + higher-dose (1 mg/kg) MTX (HDMTX); non-trauma + LDMTX; non-trauma + HDMTX.

RESULTS

Administration of MTX and MPSS treatments significantly decreased MPO activity (p < 0.05) and MDA level (p < 0.05) in the first 24 h. The MTX treatments, particularly HDMTX, were more effective than MPSS in reducing MPO activity, and MTX treatments were also more effective than MPSS in reducing MDA level (p < 0.05). The MTX treatment was more protective on large- and medium-diameter myelinated axons in minimizing ultrastructural changes in the spinal-cord-injured rats, but did not induce neurotoxicity in normal spinal cord.

CONCLUSION

The results of this study indicate that MTX treatment has a beneficial effect by reducing early neutrophil infiltration and the associated lipid peroxidation, and has significantly protective effects on the injured spinal cord tissue in the first 24 h after SCI. Given the anti-inflammatory properties of MTX, a single dose of MTX a week is used for non-neoplastic disease in humans, and MTX may have a beneficial role in the immediate management of acute SCI.

Disease-modifying agents in multiple sclerosis

Since 1993, six disease-modifying therapies for multiple sclerosis (MS) have been proven to be of benefit in rigorous phase III clinical trials. Other agents are also available and are used to treat MS, but definitive data on their efficacy is lacking. Currently, disease-modifying therapy is used for relapsing forms of MS. This includes clinically isolated syndrome/first-attack high-risk patients, relapsing patients, secondary progressive patients who are still experiencing relapses, and progressive relapsing patients. The choice of agent depends upon drug factors (including affordability, availability, convenience, efficacy, and side effects), disease factors (including clinical and neuroimaging prognostic indicators), and patient factors (including comorbidities, lifestyle, and personal preference). This review will discuss the disease-modifying agents used currently in MS, as well as available alternative agents.

Therapeutic approaches to multiple sclerosis: an update on failed, interrupted, or inconclusive trials of immunomodulatory treatment strategies

Multiple sclerosis (MS) continues to be a therapeutic challenge, and much effort is being made to develop new and more effective immune therapies. Particularly in the past decade, neuroimmunologic research has delivered new and highly effective therapeutic options, as seen in the growing number of immunotherapeutic agents and biologics in development. However, numerous promising clinical trials have failed to show efficacy or have had to be halted prematurely because of unexpected adverse events. Some others have shown results that are of unknown significance with regard to a reliable assessment of true efficacy versus safety. For example, studies of the highly innovative monoclonal antibodies that selectively target immunologic effector molecules have not only revealed the impressive efficacy of such treatments, they have also raised serious concerns about the safety profiles of these antibodies. These results add a new dimension to the estimation of risk-benefit ratios regarding acute or long-term adverse effects. Therapeutic approaches that have previously failed in MS have indicated that there are discrepancies between theoretical expectations and practical outcomes of different compounds. Learning from these defeats helps to optimize future study designs and to reduce the risks to patients. This review summarizes trials on MS treatments since 2001 that failed or were interrupted, attempts to analyze the underlying reasons for failure, and discusses the implications for our current view of MS pathogenesis, clinical practice, and design of future studies. In order to maintain clarity, this review focuses on anti-inflammatory therapies and does not include studies on already approved and effective disease-modifying therapies, albeit used in distinct administration routes or under different paradigms. Neuroprotective and alternative treatment strategies are presented elsewhere.

Secondary progressive multiple sclerosis: current knowledge and future challenges

The secondary progressive phase of multiple sclerosis (MS), which is characterised by a steady accrual of fixed disability after an initial relapsing remitting course, is not clearly understood. Although there is no consensus on the mechanisms underlying such a transition to the progressive phase, epidemiological and neuroimaging studies indicate that it is probably driven by the high prevalence of neurodegenerative compared with inflammatory pathological changes. This notion is lent support by the limited efficacy of available immunomodulating and immunosuppressive treatment strategies, which seems to be further decreased in the late stages of secondary progressive MS. No established clinical or paraclinical predictors of the transition from relapsing remitting to secondary progressive MS have been described. However, the use of quantitative MRI-derived measures is warranted to monitor natural history studies and therapeutic trials of secondary progressive MS with increased reliability. In view of the small effects of immunomodulating and immunosuppressive treatments in preventing the transition to secondary progression, the development of treatments promoting neuroaxonal repair remains an important goal in this disease.

Oral effects of low-dose methotrexate treatment

Methotrexate is used increasingly in low-dose regimes for a variety of conditions, particularly rheumatoid arthritis. While certain adverse effects of low-dose methotrexate have been described in detail, oral complications have received little attention. This article includes a summary of the uses and pharmacology of low-dose methotrexate and the mechanisms that lead to general and oral toxicity. The literature relevant to potential oral adverse effects is discussed and 7 illustrative cases are presented. The oral effects noted range from nonhealing ulcers to lymphoma-like lesions. Dental practitioners should be aware of the possible oral effects of low-dose methotrexate that have so far been largely unrecognized.

Effect of drugs in secondary disease progression in patients with multiple sclerosis

Secondary progressive multiple sclerosis (SPMS) is a form of MS characterized by continuously worsening disability with or without superimposed relapses that occurs after a variable period of relapsing remitting disease and results in limited ambulation for almost all patients. The use of interferon beta (IFN beta) for immunomodulation in patients with SPMS has been evaluated in four recent clinical trials: The European multicentre trial on IFN beta-1b in SPMS (EUSPMS), the Secondary Progressive Efficacy Trial of Rebif (IFN beta-1a) in MS (SPECTRIMS), the North American Study of IFN beta-1b in SPMS (NASPMS), and the International MS Secondary Progressive Avonex Clinical Trial (IMPACT). EUSPMS was the only trial to demonstrate a significant positive effect of therapy on disease progression as measured by the expanded disability status scale (EDSS). However, results from all studies demonstrated significant positive effects of treatment on relapse, T2 lesion load, and gadolinium enhancement. Immunomodulation with IFN beta has the potential to significantly slow disease progression and improve quality of life for patients with SPMS. While results with monthly i.v. Ig were disappointing, positive effects on disease progression have been reported with the application of immunosuppressants, especially Mitoxantrone. The risk-benefit ratio of these cytostatic agents remains controversial. New strategies addressing the important neurodegenerative aspects of the disease are urgently needed.

Azathioprine and methotrexate in multiple sclerosis

Evidence for the effectiveness of immunosuppressive agents in MS is scanty. There are few good quality trials; most have methodological limitations, such as a small sample size and short duration. Moreover, there is no consistency in treatment regimes, patient groups or outcome measures and the clinical benefits remain unclear. Although azathioprine appears to reduce the relapse rate in MS patients, its effect on disability progression has not been demonstrated. Methotrexate may alter the course of disease favourably in patients with progressive MS, but the evidence is again sparse.